A pixel art image of a mushroom

Open Circuit

This video by AlphaPhoenix blew my mind.

The basic question is very simple, how does the battery know how much current needs to pump into a circuit that is open.

The basic intuition I had from my (very limited) electrical studies is that nothing happened. An open circuit has no current at any time.

That is not the case for a small period of time, check the video!